Einstein: I will give you a question, and you will give a question to me as well. If you can’t answer my question, you will give me $1, and if I can’t answer your question, I will give you $1000.
Mr. Bean: OK
Einstein: (gives Mr. Bean a hard question)
Mr. Bean: (gives Einstein a dollar)
Einstein: Okay, your turn.
Mr. Bean: What is the animal that has 4 legs, and when he crosses a street has only 2 legs, and when he goes back, he has 5 legs.
Einstein: (thinking very long) I give up. I can’t answer that. (Einstein gives Mr. Bean $1000)
Einstein: But what animal is that, Mr. Bean?
Mr. Bean: (gives $1 to Einstein)